Commonly owned U.S. Pat. No. 6,238,372 to Zinger et al., the contents of which are incorporated herein by reference, illustrates and describes fluid control devices for the preparation of liquid drugs for administration purposes. US '372 FIGS. 1 to 19 illustrate fluid control devices including a housing with a syringe port for receiving a syringe pre-filled with diluent with or without an active chemical component, a vial adapter port with a vial adapter for snap fitting onto a vial pre-filled with powder or liquid medicament, and a drug administration port for administering a liquid drug. The fluid control devices include a rotatable flow member for providing either a mixing flow path between the syringe port and the vial adapter or an administration flow path between the syringe port and the drug administration port. US '372 FIGS. 11 to 15 illustrate fluid control devices having vial adapter ports with vial adapters intended to be rotationally detached after a mixing procedure whereupon a detached vial adapters is intended to be discarded together with its attached spent vial. Such fluid control devices are commercially available under the registered trademark MIXJECT® from Medimop Medical Projects Ltd., Ra'anana, Israel. MIXJECT® product information is available at http://www.westpharma.com/products/medimop/Information/mixject.pdf.
For the sake of convenience, the following two terms are employed hereinafter in the specification and claims: “Preparatory assemblage” referring to a MIXJECT® fluid control device with its vial adapter and an attached vial pre-filled with powder or liquid medicament and a syringe pre-filled with diluent for mixing with the medicament, and “liquid drug assemblage” referring to the preparatory assemblage with its syringe filled with a predetermined dosage of liquid drug and without its detached vial adapter and attached spent vial. The liquid drug assemblages are typically inserted into auto-injectors for administering their entire liquid drug contents. The instructions of use for a MIXJECT® fluid control device for processing a preparatory assemblage into a liquid drug assemblage are as follows:
Step 1: User snap fits a fluid control device's vial adapter onto a vial pre-filled with powder or liquid medicament.
Step 2: User inserts a syringe pre-filled with diluent into the syringe port to form the preparatory assemblage.
Step 3: User injects the diluent into the vial.
Step 4: User agitates the preparatory assemblage to mix the diluent with the medicament to form the liquid drug.
Step 5: User inverts the preparatory assemblage.
Step 6: User aspirates the liquid drug into the preparatory assemblage.
Step 7: User rotates the vial adapter to remove same and attached spent vial to convert the preparatory assemblage into the liquid drug assemblage.
Step 8: In the case of certain liquid drugs, user ejects some liquid drug contents to leave a predetermined dosage of liquid drug for administration purposes.
It has now been found that some users have encountered difficulties in manually processing preparatory assemblages into liquid drug assemblages as now explained. Pre-filled syringes typically include air with their diluent contents which often leads to the presence of one or more air bubbles in a liquid drug assemblage's liquid drug contents thereby burdening users to remove same prior to administration. Exemplary relative volumes of diluent and air in 1 ml pre-filled syringes include 1.2 ml diluent and 0.4 ml air. In cases of liquid drug assemblage's liquid drug contents containing some air bubbles, users typically hold a liquid drug assemblage upright with its needle facing upwards and flick on the syringe's barrel to break up any air bubbles into smaller air bubbles at the top of its syringe which they then eject. However, it should be noted that some freshly mixed liquid drug contents start bubbling in a liquid drug assemblage after a certain length of time due to a chemical reaction between a medicament and a diluent including an active chemical component, thereby re-introducing air bubbles into the liquid drug contents.
Some users may inadvertently cause foaming of a liquid drug thereby requiring a long settling period before the processing of a preparatory assemblage can be finalized and its liquid drug contents is suitable for administration. Such foaming can be caused by injecting diluent into a vial too quickly or agitating a preparatory assemblage too violently. Conversely, particularly in the case of a powder medicament, insufficient agitation may lead to some of a vial's contents not being dissolved. Additionally, some users occasionally inadvertently aspirate an insufficient volume of liquid drug prior to detachment of a vial adapter which is typically detrimental to an intended medical treatment.
Some syringes have graduations which are semi-circular and, depending on the Luer connection between a syringe and a MIXJECT® fluid control device, can face downwards when a preparatory assemblage is inverted to aspirate liquid drug contents thereinto such that a user cannot see them. Moreover, some users have difficulty reading a syringe's graduations to accurately determine its volume of liquid drug.